化工学报2019，Vol.70Issue(8)：2961-2970,10.DOI:10.11949/0438-1157.20190286
射流式涡发生器强化矩形螺旋通道内流体换热机理
Heat transfer enhancement mechanism of jet longitudinal vortex generator in helical channel with rectangular cross section
摘要
Abstract
This study proposed to use a jet longitudinal vortex generator (JVG) to enhance heat transfer capability of fluid in the helical channel. Fluid flow characteristics in the helical channel with rectangular cross-section and installed with a JVG were measured by a 3D Laser Doppler Velocimeter (LDV). The curvature of helical channel is δ=0.134. The experimental results were in good agreement with the simulated results. The evolution process of the composite secondary vortices in the helical channel with a JVG and the attenuation process of the jet in the helical channel were obtained. The results show that the impact and entrainment of the jet changes the structure of the common-flow-up (CFU) vortices in the smooth helical channel. And a pair of common-flow-down (CFD) vortices is formed in the initial stage of jet. With the development of the flow in the helical channel, the CFD vortices undergo a process of rapidly producing, slowly decomposing and gradually dissipating. When the speed ratio of the jet stream to the main stream is between 1.48 and 4.02, the effect of jet can reach a distance of 40—74 times dh along the mainstream direction in the helical channel. Here dh is the equivalent diameter of helical channel. The effect of JVG improves the synergy between the velocity fields and the temperature fields in the helical channel, thus heat transfer enhancement can be achieved. Within the scope of the study,the average Nusselt number of the heat exchange wall is increased by 28% to 248% relative to the single spiral channel.关键词
螺旋通道/射流/流动/传热/数值模拟/场协同Key words
helical channel/ jet/ flow/ heat transfer/ numerical simulation/ field synergy分类
能源科技引用本文复制引用
李雅侠,王霞,张静,张春梅,龚斌,吴剑华..射流式涡发生器强化矩形螺旋通道内流体换热机理[J].化工学报,2019,70(8):2961-2970,10.基金项目
国家自然科学基金项目(51506133,51406125) （51506133,51406125）
辽宁省教育厅科学研究项目(LQ2017001) （LQ2017001）
辽宁省自然科学基金面上项目(553649468458) （553649468458）
